Before following this guide you must follow the guide linked below.

Then close the project and go to the link below and download and unzip the folder, then copy the new folder that you unzipped and then navigate to your project files (This is where the content, Config and Project Shortcut files are located) and paste in the folder you copied.

If you want to learn how to use the new wave spawner check out the feature guide below, you can also hover over the variable names in the AIWaveSpawningVolume to get detailed tooltips that explain what they do.